What's the latest on tilt rotors? [Archive] - Page 2

John Eacott

19th Mar 2002, 03:30

LZ said: "The (Apache) helicopter that is designed to withstand a direct hit from a 23mm HEI round was engaged with some small arms fire in Afghanistan and high tailed it out of the area.". .. .On what do you base that assertion? If it was the well publicised article in The New York Daily News, by that toe rag Leo Standora, then you should be aware of the other side of the coin, as posted on numerous NG's:. .. ."1. Six Apaches defended the downed MH 47. .. .2. What the reporter failed to mention is that one Apache had its Tgt Acq Designation Sensor blown off by an RPG that did not explode and stayed in the fight shooting the 2.75 nails and 30mm. .. .3. A second Apache took an RPG in the engine area, had an oil line severed and hits to the xmsn causing the xmsn to go dry. The AH 64 stayed on station firing up all ammo, and returned to base THIRTY EIGHT MINUTES after all oil was out of the xmsn.. .. .4. One Apache had its tail wheel blown off, all AH 64s from 3/101 were shot to Sh*t AND NOT ONE CREWMEMBER WAS LOST! The Apache is a flying tank.. .. .5. The lying a$$ low rent piece of $hit Leo Standora states the 64s were taken down by rifle and pistol fire. The effective fire was rocket propelled grenades, B 40 RPGs and the acft stayed on station after being hit.. .. .6. This is just another one of those, "so what is your point?" pieces of $hit coming from the media that is ill researched, and perpetuated by a newspaper so low rent I won't put in my dog's cage for them to $hit on. A$$hole maggot media puke.. .. .THESE Apaches are in Dick Cody's Division, the 101st Airborne. Cody MAKES sure the Apache crews are highly trained, spirited, highly motivated warriors. Cody is the one that led the Apaches into Iraq, behind the MH-53Js and blew away the radar site, 0100, 19 Jan 1991.. .. .These USMC Cobras have NO WHERE near the night fighting capability of the Apaches, so blow that $hit up someone else's skirt. Additionally, AFTER THE FIGHT is over is no time to be bragging about the AH 1W. Where were they when the paper was blank? They would NOT have survived in that fight. Marines aren't in the real fight, so get over it.. .. .I got this piece of $hit off a USMC selected reading file of news stories I get every day from USMC. IT IS TIME FOR THE FKING USMC TO UNDERSTAND WE ARE ALL IN THIS TOGETHER, and quit pouting because they got put back on their boats so the larger United States Army with longer staying power could be deployed.. .. .The Marines must have forgotten about how they did not support the SF at Lang Vei in Jan 68 when it was being overrun by tanks. The United States Army Special Operators HAVE NOT FORGOTTEN that sterling USMC effort.. .----------- Mike Sloniker, US Army retired.". .. .Apologies for the language, this is as posted to refute the ill founded knocking of the Apache. Whilst I have no personal views/experience either way, it behoves some posters to be less dogmatic in their criticisms, especially when they have little or no background on which to make their assertions.

ShyTorque

19th Mar 2002, 04:21

Dave J,. .. .Thanks for the link, interesting page.. .. .Next, the Fairey Rotordyne, now THAT was a project that could have worked.

Lu Zuckerman

19th Mar 2002, 06:29

To: John Eacott. .. .Quote:. .. .“LZ said: "The (Apache) helicopter that is designed to withstand a direct hit from a 23mm HEI round was engaged with some small arms fire in Afghanistan and high tailed it out of the area.". .. .“On what do you base that assertion? If it was the well publicised article in The New York Daily News, by that toe rag Leo Standora, then you should be aware of the other side of the coin, as posted on numerous NG's:”. .. .Response:. .. .The action in which the Apaches “high tailed it” was photographed and described by a news broadcaster on CNN who accompanied the ground troops on Operation Anaconda.. .. .When deployed in the Gulf War the Apaches never engaged the enemy in the manner in which the helicopter was designed. Most of their operations were as a standoff weapon firing their chain guns from several thousand meters from the target. The helicopter was designed to engage the enemy at close quarters. That is why the US Army specified the 23mm survivability requirement. They also operated in a standoff mode while firing their missiles. If you ever saw the news footage of Apaches in Desert Storm you will have seen them aligned ten or twelve abreast firing their weapons and not directly engaging the enemy. In watching the CNN footage regarding Operation Anaconda I was surprised that the Apaches got so close to the enemy and if they took the damage that you described then it attests to the design and construction of the airframe. Regarding your comment about the Apache staying on station after loosing all of his gearbox lubricant the helicopter is designed to do just that. Inside each gear in the transmission there is a felt wick which holds a large amount of oil. If the transmission oil is lost the trapped oil will be discharged through small holes in the gear by CENTRIFUGAL FORCE and this reserve oil supply will last for a minimum of thirty minutes. The pilot that stayed on station was not being heroic he was flying the helicopter the way it was designed.. .. .Quote:. .. .“Whilst I have no personal views/experience either way, it behoves some posters to be less dogmatic in their criticisms, especially when they have little or no background on which to make their assertions”. . .. .Response: . .. .I worked as a contract consultant on the Apache during the initial response to the Army proposal where I set up the Maintainability program for the helicopter defining what was necessary to incorporate in the design to meet the Army’s’ design for maintainability goals. I was called back a second time to respond to the Army’s queries relative to the program plans. Upon completion of that assignment I went to work for Bell Helicopter as a manager of technical assistance (Product Support). That lasted three years and upon my return to the States I went to work at Hughes Helicopters as supervisor of Maintainability design overseeing the design for Maintainability for the whole aircraft. I believe that gives me the authority to make certain statements about the Apache.. .. .Now if you want to discuss the low availability and poor maintainability of the Apache we can start another thread.

Cyclic Hotline

19th Mar 2002, 09:18

Anyway, back tothe original topic.. .. .It appears a Sikorsky/Bell tiltrotor compromise may have been reached.. . <img src="http://us.f1.yahoofs.com/users/f5c8b277/bc/My+Photos/S+61+T.jpg?bc4ow58A3xdBAbsb" alt="" /> . .. .Courtesy of Rotorhead over at <a href="http://www.canadianaviation.com/" target="_blank">Canadian aviation</a>

tgrendl

20th Mar 2002, 03:29

Lu,. .. .Like your comments most times, always make me think a bit.. .. .The Apache stuff is off though.. .. .Attack helos are not designed to "fight the enemy up close" they are designed to kill the enemy using the last third of the appropriate weapons useable range.. .. .Every baby attack pilot knows what BRASSCRAFF stands for. It's fundamental to fighting the aircraft.. .. .As a contractor we could swap out a blade and have it flying within limits in about an hour at the most. That's real time not flight time. It usually took two .2 or .3 flights to do that. The changeout time for the blade was around 10 minutes with two people.. .. .Don't blame the airframe for the inefficient use and training of personel in the service.. .. .The strap pack issue you mentioned earlier is valid but not for the stated reason.. .. .The 500 series aircraft use the same type strap pack but don't suffer from the same breakage problems.. .. .But put those aircraft on a tricycle system and have people taxi them around everywhere and they would.. .. .We may be short training, experience, spares and flight time but those guys fighting the aircraft weren't short of guts.. .. .keep up the good posts ! <img border="0" title="" alt="[Big Grin]" src="biggrin.gif" />

Flying Lawyer

20th Mar 2002, 03:43

Just in case anyone is wondering why Nick Lappos, who usually devotes an enormous amount of his time answering and explaining points on Rotorheads has not responded, he is on vacation in the UK at present.. .I had dinner with him last night - his conversation is as impressive and fascinating as his contributions to the Forum.. .. .Lu says ".......... just like Nick who works for Sikorsky and who supports their products." . .It's true Nick is proud of Sikorsky Lu, but equally he never once 'knocked' other manufacturers. He has such enthusiasm for helicopters that he seems to want everyone to succeed, not just Sikorsky.. .The forum has an enormous asset in having someone of his distinction both as an engineer and as a test pilot contributing to Rotorheads.

Lu Zuckerman

20th Mar 2002, 08:41

To: tgrendl and All. .. .First of all I would like to state that I was not disparaging the pilots of the Apaches in either Desert Storm or in Afghanistan. I have a great deal of respect for not only combat pilots but all pilots. I had the opportunity to become an Army Aviator and I turned it down.. .. .Evidently the Army (my opinion) had something to prove. The first time the Apache was in combat was in Panama and they performed very poorly due to the high humidity which worked into the electronics suite and had to be removed using a hair dryer. In Desert Storm the Apache was not allowed to engage the enemy directly because of many problems including low reliability. The next time the Apache was involved in a combat situation was in the Balkans and in that theater the Apaches were not allowed to fly patrols because of heavy ground fire as well as poor performance. To counter your point of the Apache being used in a standoff situation the Apache was the Army’s A-10 which engages the enemy well within the effective range of small arms and machine gun fire. That was the concept promoted by the Army especially since the Cheyenne program was cancelled. The Cheyenne had only a Mini Tat and Tow missiles, which required fairly, close in flying. When the Cheyenne was cancelled the AAH program was born. The Apache was originally designed to carry TOWs and air to ground rockets along with the chain gun. It wasn’t until the design had been finalized that the Hellfire Missile was made available for installation on the Apache and this gave it true stand off capability.. .. .My reason for addressing the poor reliability and maintainability is twofold:. .. .1) Hughes Helicopters intentionally held back a report to the US Army, which addressed twenty-seven different design faults that would directly effect the reliability and maintainability of the Apache. The report was released only after the Army accepted the Apache as designed. Since the report was time sensitive it was overtaken by events. In operation all twenty-seven deficiencies manifested them selves. The engineering department would not cooperate with the product assurance department so when a design defect was noted it was ignored. Another trick used by engineering was to intentionally withhold the drawings for sign off by R&M until they had accumulated several hundred and they would tell us to sign them off within one hour or, they would sign them off for us. They had no regard for R&M because it was totally alien to the Hughes Helicopter engineering management.. .. .2) My comments about the poor reliability and maintainability of the Apache after it was fielded were based on a report made by the Government Accounting Office (GAO). The title of the report is APACHE HELICOPTER Serious Logistical Support Problems Must Be Solved to Realize Combat Potential. Many of the 27 items described above were identified in this report. The findings of the report were in accordance with a request from the US Congress.. .. .Regarding the similarity between the strap packs on the model 500 and the Apache they are similar in only one way. They are constructed of laminations of stainless steel that withstand CENTRIFUGAL FORCES and, they allow pitch changes and flapping. Because of their construction they also allow leading and lagging. The basic designs are different but the concept is the same. The major differences are in the blade design. The 500 I believe has symmetrical airfoils and the Apache has unsymmetrical airfoils. The unsymmetrical airfoil makes the Apache blade unstable due to movement of the center of pressure. Another thing is the Apache blade and those of the 500 have a negative twist. With the twist the angle of attack is different for each blade station and this makes the center of pressure move differently for each station thus making the blade unstable. This instability causes the rear strap pack hit the rotorhead causing the strap pack elements to fatigue.. .. .Here are figures quoted in the GAO report dealing with MMH to perform a specific job.. .. .Because the PPRuNe forum doesn’t print tables I’ll try to accommodate the forum.. .. .Component. .1) Main Rotor Blade. .2) Main Rotor Strap Pack. .3) Tail Rotor Swashplate. .. .Maintenance Man Hours. .1) 14-26. .2) 32-44. .3) 8. .. .Aircraft downtime. .1) 8 hours. .2) 3-4 Days. .3) 8 Hours. .. .The design spec required that each of these elements among others be removed and replaced within 30 minutes using no more than two men.. .. .If you can do it faster, more power to you. The Army reflecting US Army mechanics quoted these figures.. . . . <small>[ 20 March 2002, 15:47: Message edited by: Lu Zuckerman ]</small>

UNCTUOUS

28th May 2002, 20:55

Part 1/2
Crucial test
By BOB COX
Star-Telegram Staff Writer
May. 27, 2002

When the V-22 Osprey lifts off again Wednesday for a crucial round of flight tests, Bell Helicopter Textron and Boeing Co. officials hope to show that they have fixed myriad mechanical flaws that contributed to a December 2000 crash and the aircraft's grounding. But there is a bigger question that the manufacturers, the Marines and the Pentagon must answer in the coming months about the V-22.Can the revolutionary tilt-rotor, which takes off like a helicopter and flies like an airplane, perform hard combat maneuvers without going into a deadly roll? A series of reports presented to Pentagon officials last year suggests that the V-22, when flown like a helicopter, possesses unforeseen characteristics that can cause it to lose lift on one side and go into a roll. Close to the ground, that would probably cause a crash. Concerns about unusual aerodynamic problems have haunted the Osprey since April 2000, when a V-22 suddenly rolled out of control and crashed into the desert at Marana, Ariz., killing all 19 Marines aboard. The Marines blamed the accident on pilot errors that caused the aircraft to undergo a turbulent condition called vortex ring state. A top Marine general dismissed the accident as "nothing new ... that we haven't seen in helicopters." But tests performed for several months afterward showed that there appears to be something different about the V-22.

Seven times during 21 high-altitude test flights at the Navy's Patuxent River air base, a V-22 suddenly began to roll when it was flown like the craft involved in the Arizona crash. "There were some long faces on Marine officers at the Pentagon the first time that happened," says Philip Coyle, the former head of the Pentagon's weapons testing office who has frequently raised questions about the V-22. "It got everybody's attention." In one case, a V-22 reached an 84-degree bank, its wings nearly perpendicular to the ground, according to a Bell/Boeing presentation to the Pentagon's "Blue Ribbon Panel," which investigated the aircraft after the 2000 accidents. A Pentagon source familiar with the V-22 testing says the aircraft lost 2,000 feet of altitude before the pilots regained control - a margin for error that probably would not exist in a military operation. "There is a flight characteristic here that doesn't exist in a helicopter," says J. Gordon Leishman, an aerospace engineering professor and helicopter aerodynamics expert at the University of Maryland who has studied tilt-rotor aircraft. Officials with Bell dispute that conclusion. They say the V-22 is safe when flown within its prescribed limits. The V-22's chief test pilot, Boeing's Tom MacDonald, acknowledges that valid questions about the aircraft remain to be answered. But MacDonald, who will be at the controls often during the upcoming flight tests, says he's confident that the V-22 will be proved safe and effective.

"There's no doubt in my mind," McDonald says. "None whatsoever. We're going to go out and and fly that aircraft as aggressively as we can and as aggressively as we think other pilots will do it." Flight tests were expected to begin in April and were delayed a second time in early May. The Marines announced Friday the first flight in 18 months will take place Wednesday. The tests, which will be conducted at the Patuxent Naval Air Station in southern Maryland, could last two years. A lot is riding on the flight tests for Fort Worth-based Bell, which employs nearly 5,800 workers in the area and about 250 in Amarillo. Bell officials long ago bet the company's future on the tilt-rotor technology of the V-22. They had even laid plans for a civilian version, though development of that aircraft has been drastically scaled back until the verdict is in on the V-22.

Pentagon officials have indicated that the new testing amounts to a last chance for the V-22. They have said that if problems persist, the program will be killed. The two crashes, eight months apart, led to a flurry of investigations and reviews of the V-22 program. Two Pentagon-appointed panels endorsed the Osprey last year, saying it had no fundamental safety problems. But both called for much more extensive flight tests. The `Star-Telegram,' in consultation with outside experts, reviewed many of the technical reports made to both the Blue Ribbon Panel and a review panel headed by a top NASA official. Officials with Bell Helicopter declined to discuss the reports in detail.

Although final reports by the two review panels touched on some of the issues, none were highlighted as major concerns. Others were dismissed. The panel headed by Henry McDonald, administrator of the NASA space agency's Ames Research Center in California, concluded in its public report that "there are no known aeromechanics phenomena that would stop the safe and orderly development and deployment of the V-22." Some helicopter experts have been sharply critical of that conclusion. "The McDonald report looks to me like a whitewash," said Dave Jenney, the retired chief engineer for Bell competitor Sikorsky Aircraft Co. "It glosses over some things" that are crucial for a military airplane, he adds. McDonald declined to discuss the panel findings for this article. "He feels it's a thorough and complete report," NASA spokeswoman Ann Hutchinson says. The studies failed to convince some top Pentagon officials of the V-22's safety. As recently as May 2, Defense Undersecretary E.C. "Pete" Aldridge, the government's chief weapons buyer, said he remained skeptical about the tilt-rotor's safety and reliability. "We have not done a lot of the tests of the V-22 in combat maneuvering," Aldridge said in a meeting with reporters. "We don't have many friends up there in the Pentagon," admits MacDonald, the Boeing test pilot, who has acted as a spokesman for Bell and Boeing on the upcoming flight test program.

UNCTUOUS

28th May 2002, 20:57

Much of the debate about the safety of the V-22 stems from the Arizona crash. What happened that April night shocked helicopter experts. The pilots were trying to land when the V-22, which was about 300 feet off the ground, rolled over on its back and plunged into the ground. The Marines' investigation of the crash quickly concluded that the pilots allowed the V-22 to descend too quickly with too little airspeed. As a result, the plane got caught in its own rotor wake, a condition called vortex ring state that causes a rotor to lose lift or to stall. The phenomenon has been blamed for helicopter accidents only rarely and previously received little scientific attention. The official crash report concluded that probably just one rotor underwent vortex ring state and stalled. Within a couple of seconds, that caused the plane to go into the roll, and the pilots had no chance to recover.

It had never occurred to anyone that just one rotor might stall and cause the V-22 to roll. "It's something was that was not on our radar screen at all," said MacDonald, the flight test pilot. (The Marines' handling of the crash investigation is the subject of an inquiry by the Pentagon's inspector general, after a Marine officer alleged improper actions by other officers. A Marine spokesman says the allegations do not affect the conclusion about the cause of the crash.)

In the months after the crash, Bell and Boeing began the special flight tests at Pax River to explore the vortex ring state. That testing was only partially complete when all V-22s were grounded after the December 2000 crash. Bell and Boeing, in their reports to the review panels, say the tests show that the V-22 can recover from a roll if the pilot simply rolls the engines forward to gain speed. But that can take seconds and hundreds of feet of altitude - time and space that even MacDonald concedes may not be available. "If you're close to the ground, it's a bad thing," the Boeing pilot says.

Based on the limited flight testing, the Marines and Bell/Boeing insist that the vortex ring state will not be a problem if the V-22 is flown within the prescribed limits. The V-22 flight manual says pilots should descend no faster than 800 feet per minute when flying at speeds of 40 knots or less - a slow, gradual descent not unlike that of a commercial airliner. MacDonald agrees with that guideline, although he says much more flight testing is needed.

"We're going to do a whole lot more of that when we get back to flying," he said. But the experts who've raised concerns about the V-22 say other test data presented in reports to the review panels strongly indicates that controlling the rate of descent does not eliminate the vortex ring state.

Flight simulator tests show that even with much slower descent, trying to maneuver a V-22 abruptly - making a hard turn or a sudden pull-up to abort a landing - could cause it to roll. Evidence of this was included in a special presentation that NASA's McDonald made to Aldridge in August. That presentation, which has not been made public but was obtained by the `Star-Telegram,' shows that in a simulator test the boundary between safe flight and vortex ring state all but disappears when a maneuver is attempted. Still other simulator tests show that when a pilot attempts an abrupt maneuver, the V-22 may spin out of control in as little as two or three seconds.

That's not much of a margin for error, says Coyle, whose office presented the data to the Blue Ribbon Panel. "A point we made ... was when a pilot is doing a quick stop maneuver, a pull-up, it's because something else is going on," Coyle says. "He's being shot at or he's trying to rescue someone. He's concentrating. If in the midst of that concentration something else occurs, he may not be able to react." In the Arizona accident, the pilot flying the V-22 did not lose control until he tried to turn the airplane to stay in formation.

Boeing's MacDonald concedes that, in theory at least, maneuvers could narrow the safety margin. "We're not sure," he says. "We don't believe it's significant. But we're going to test the hell out of that." When shown the charts that suggest that hard maneuvers could cause the V-22 to stall and roll, several retired Bell test pilots and engineers who worked on the V-22 said the aircraft was not designed for hard maneuvers and should not be flown that way. But Grady Wilson, a combat veteran of the Vietnam War and a former V-22 test pilot for Boeing, said that telling an Osprey pilot he can't maneuver in the heat of battle or even the chaos of military operations is unrealistic.

Wilson agrees that the V-22's maneuverability needs to be thoroughly tested. "As I flew it, we babied it. You had to be really gentle with it." Leishman, the Maryland professor, used a computer to simulate what happens with the rotors of helicopters and an aircraft like the V-22. His findings, in a paper recently published by the American Helicopter Society, show that a tilt-rotor aircraft has more complex aerodynamics than a helicopter. During rapid descent or maneuvers, he believes, it's typical for one rotor to get caught in the other's wake. When that happens the two rotors produce widely varying amounts of thrust.

"The thrust fluctuations lead to the roll response" long before the aircraft should reach vortex ring state, says Leishman, who briefed the NASA panel on his research. Leishman, Coyle and others say the V-22's problems may be related to something less exotic than vortex ring state: a propensity for the rotors to stall easily because they cannot generate enough extra thrust at critical moments to maneuver the airplane. Bell and Boeing engineers, in a written response provided to the `Star-Telegram,' denied that the V-22 is more prone to stall than helicopters. MacDonald says the V-22 will be capable of combat maneuvers. "We do expect people to be under duress in the operational world," he says, "and the aircraft has to be forgiving" of pilot mistakes. "The penalty for a good faith violation of a boundary can't be the loss of an aircraft and the crew," MacDonald says. A Marine spokesman, Capt. David Nevers, says the Marine generals still believe that the V-22 is safe and the right aircraft to replace old troop-carrying helicopters. "Our faith in this aircraft has not wavered," says Nevers, although he adds that the Marines "recognize there is more to learn." MacDonald says the upcoming flight tests, which could take 18 months to two years, will answer the questions and, he believes, show that the V-22 can perform all the duties of comparable helicopters "and then some." The tests to check out the vortex ring state and maneuver issues, are not scheduled to begin until late summer or fall, when a specially modified V-22, heavily instrumented for the purpose is ready to fly.

Bob Cox, (817) 390-7723 [email protected]

Briefings to the Blue Ribbon Panel are available at www.acq.osd.mil/sts/v22/archives.htm

Professor Leishman's paper on vortex ring state: www.enae.umd.edu/AGRC/aero.html.

From this link (http://www.dfw.com/mld/dfw/business/3346049.htm)

bliptune

29th May 2002, 00:58

The author does a disservice by stating that 7 of 22 attempts at reproducing the problem situation drew long faces on the marines or people overlooking the test.. in all cases the maneuvers were done outside of the prescribed limits, i.e. pilot error!

I also dont agree with the military analysis that in the heat of battle you can't expect the pilot not to push the envelope. If you are on a motorcycle with a lot of power available you can't just wind on as much power as you like to get away from someone chasing you, but have to ride within the prescribed limits of available grip. Similarly the osprey should be flown with full awareness and within its limits.

Link, The V-22 tiltrotor
http://www.helicopterpage.com/html/tiltrotor.html

Nick Lappos

29th May 2002, 03:28

bliptune,

Regarding that link in your post, I don't know where the author got his info, but it is really inaccurate!

The author really does not understand the issues, and seems to mash up a bunch of rumors and partial answers into a dim understanding of the issues surrounding V-22 as we know it today.

For example, see his explanation of the autorotation issue, where he resolves it by proving that there are freewheel units in the drive train so everything is ok! The site is way too nieve to be of much use, I think.

Nick

Lu Zuckerman

29th May 2002, 03:55

For example, see his explanation of the autorotation issue, where he resolves it by proving that there are freewheel units in the drive train so everything is ok! The site is way too nieve to be of much use, I think.

It may have been naive of the author of the V-22 article in stating that the presence of free wheeling units permits the V-22 to Autorotate like a helicopter but what helicopter has a descent rate of 4-6000 feet per minute and the inability to arrest this descent rate.

:confused:

Dave Jackson

29th May 2002, 05:08

Tomorrow's VTOL aircraft will be twin-rotor.

The only indeterminate is the configuration(s).

:eek:

Any bets?

:)

Barannfin

29th May 2002, 05:58

I was just wondering at what speeds the conversions from helicopter to plane are and how they go about that.

Also about pilots having to push their aircraft in battle, I would have to say that the people who I have talked to and thinking about it myself, if you are underfire you wanna make yourself as hard a target as possible, coming down on approach to your LZ at a nice 40kts and not being able to manuever sounds pretty restrictive to me, And scary. Sure the A/C shouldn't be flown outside their limits but if the limits are this restrictive it just doesnt seem to lend itself well to combat.

Just my 2 cents.

SASless

29th May 2002, 06:34

Push the aircraft to its limits or beyond in combat?

I was only a tandem rotor trash hauller and not a gunship pilot but I am absolutely positive that at some time in history....each one of us did just that and usually more than just once. When the bullets start hitting home or streaking by your precious parts....combat pilots are going to do whatever they have to to avoid becoming battlefield debris.

We owe it to the future generation of American combat pilots to provide them with the very best in hardware to do their jobs. If the Osprey is unable to perform in such an environment then we should scrap the program. I say test the hell out of it...and determine exactly where the limits are and make a decision at that time without any consideration for reputations, political gain, or economical considerations for the manufacturer. The only criteria is that we provide our war fighters with the very best tools we can....something that will take them to the fight and bring them home again.

UNCTUOUS

29th May 2002, 10:24

Professor Leishman's papers seem to bear out exactly my early misgivings about the inherent aerodynamic flaws - including the hazards of not testing specifically and just number-crunching prosaically toward an expectation. I don't envy Tom McDonald now because it rightly falls to him to try and prove that it can be operated within safe limits - but I honestly doubt that it can - certainly not as a battlefield vehicle and IMHO, not even to a safe civil standard. I just hope he (TM) doesn't find out the hard way. I had heard about some of the frights that the TP's were having at Pax River and I really wonder how the system can morally expect them to press on with these tests without a bang-seat mod. John Farley says that an ejection seat could be fitted and that there is a design extant (maybe Boscombe Down or Martin Baker). I certainly would not go fly these trials without being properly "seated" and I doubt JF would either. It's just not fair to task people to do that, no matter how gradually you temper the profile and approach the problem.

AsymmVR is quite a lethal evolution - without considering the other hardware and software ailments that can crop up unannounced in flight-test, whether testing the boundaries of the envelope or not. Having a seat would be more than just "nice".

bliptune

30th May 2002, 16:39

So how did the testing go yesterday, and where can we find accurate and up to date information on the osprey?

turboshaft

31st May 2002, 00:28

http://us.news2.yimg.com/us.yimg.com/p/ap/20020529/capt.1022712960.osprey_tests_mdad107.jpg

MV-22 Osprey Resumes Flying
(US Naval Air Systems Command May 29, 2002)

The MV-22 Osprey took to the skies today here for the first time after being grounded for over 17 months following the tragic Dec. 11, 2000 mishap. The first MV-22 test aircraft to resume flying has improvements in its hydraulic and flight control software systems that make it practically a brand new aircraft and the safest Osprey yet, according to V-22 program officials.

"The long awaited return to flight was a success. The Osprey not only performed what today’s test plan called for but exceeded our wildest expectations," said Col Dan Schultz, V-22 program manager. Today’s flight plan called for the aircraft to take off, hover, and land.

After successfully completing several vertical takeoffs, landings, and hovering maneuvers over the runway, the pilots conducted rearward and sideward flights to check the aircraft’s maneuverability in helicopter mode. The pilots gradually built up maneuver speeds up and down the runway, went into landing pattern circuits and began conversion work. Later in the afternoon, the Osprey’s encore performance included a full conversion to airplane mode at level flight speeds of 250 knots. The Osprey logged nearly two and one half hours of flight time today and returned in full up flight status.

Tom MacDonald and Bill Leonard, senior Bell Boeing V-22 Integrated Test Team pilots, who have a combined total of 13,000 flight hours in both fixed and rotary wing aircraft and over 500 hours each in the MV-22, took the aircraft through a series of maneuvers to evaluate its handling and performance. Part of this series included converting out from helicopter to airplane mode to take standard vibration measurements to check out the tracking and balance of the individual blades of the two proprotors. This "test card" for the first flight series follows the Osprey’s methodical and event driven approach to safely return the aircraft to flight testing.

"Along with everyone else on the V-22 test team, we are excited about being back in the flight test business. We are proud of the extensive safety and reliability enhancements to the Osprey’s design, which was made possible by the concerted efforts of many people throughout the NAVAIR, Bell Boeing, Rolls Royce and supporting contractor teams," asserted MacDonald.

Leonard shares the excitement of being back in the air and moving forward with flight testing. "I'm dedicated to the concept and believe tilt rotor technology will be as important to aviation as the advent of the jet engine. This aircraft has potential that we in the aviation community have yet to understand let alone exploit. I've been actively engaged in military and civilian aviation for over 35 years, flown well over 100 different aircraft and truly believe that this technology, if exploited properly, will impact both civil and military aviation to an incredible degree."

Today’s flight marks the beginning of an 18-month developmental flight test plan here that will validate the engineering and design changes made to the aircraft and continue with developmental testing that will further test such areas as vortex ring state boundaries, dynamic shipboard compatibility, formation flying, and low speed hovering and landing conditions. Other areas to be tested include the aircraft’s icing, cargo handling and radar warning systems. A total of 1800 flight test hours are scheduled over this period of time using seven MV-22 aircraft.

Good job guys.
t/shaft

ETOPS773

31st May 2002, 09:42

Great news..I agree they should thrash them well above their limits,really beat them about and see what it can really handle.

I think it`ll be a success.fingers crossed.

CRAN

11th Sep 2002, 22:08

I was lucky enough to have the opportunity to fly a XV-15 Tilt-Rotor in a high fidelity research simulator yesterday and it got me thinking.....

I have never been a big fan (geddit BIG FAN) of the tilt rotor concept at all, its not a good aeroplane, and its a terrible helicopter. So is it worth the technical difficultly?

With the ERICA and EUROTILT programs and the V22 & BA609 supposidy on the way, sooner or later some of us will be asked/expected to fly these things so I though it might be a good time to have a general chat about them.

I'll start things of with my two-cents....

Starting from the ground and then lifting into the hover and doing a spot of hover-taxiing I found the XV-15 to be really easy to fly (admittly I was getting lots of help from the spurious black boxes on board) but even so no big deal....very stable. The thing was very docile in yaw....lot's of pedal required to get it turning on the spot thanks to the tonne of engine and prop at the end of each wing! Flying around was just as easy and VERY VERY fast 260kts!

I have often wondered how the controls are laid out in a Tilt rotor - it's actually really neat, the collective remains as a collective in all flight regimes - up and down in helicopter mode and fast or slow in plane mode. The cyclic is a cyclic in heli mode but converts to being a stick/yoke in plane mode - the electronics handle the blending of the controls in transient speed ranges. The nacelle tilt in this set-up was handled by a coolie hat switch on the cyclic - three positions.

While everything was easy enough with an instructor talking me through the systems as I flew, I can't help thinking that the failure modes for these things are so much more complex. So complex in fact that the pilot wouldn't be able to react quick enough (to a complecated situation) to be able to do anything useful.

Furthermore, the differential ring vortex problem will also no doubt be a real danger for these craft, bank in helicopter mode at low forward speed and all of a sudden one rotor is in ring vortex state - WOLLOP.....Ouch!

I've also heard lot's of mutterings that the range and payload of real incarnations of these aircraft are also marginal.

What do you think......are they worth the bother? Would you fly them? Would you tell your granny to fly in one? Any real tilt rotor pilots out there?

CRAN
:eek:

Lu Zuckerman

6th Dec 2002, 16:24

The USMC has stated that if the V-22 enters a VRS situation it can be easily corrected by tilting the rotors 15 degrees which they state takes about 2 seconds.

My question for the experts is, can the V-22 encounter VRS while in a hover and especially in a moderate headwind? My reason for asking is what happens if the V-22 enters VRS while making a hoist pick-up over water or land where it must maintain a fixed position.

:confused:

heedm

7th Dec 2002, 04:01

No.

Entering VRS requires a descent, the rate of which depends on disk loading and power applied.

VRS is a risk in all rotorcraft, pilots must be able to identify the incipient stages, know the corrective actions, and fly in profiles which prevent it from happening. Problem with the V22 is that it has demonstrated rapid catastrophic results that weren't originally anticipated (to the best of my knowledge).

I expect that VRS will not be a player in the future of V22 flight if training and procedures are appropriate.

--------------
Matthew.
[email protected]

PS. Welcome back, Lu.

Tail Bloater

10th Dec 2002, 13:14

From memory the BIG problem for the V-22 when VRS is encountered is that it can happen on one side and not on the other, and I remember that this was the complexity in one of the accidents causing an uncontrolable roll from which the normal recovery action, that of going for forward speed/reducing pitch was not going to work. I would have expected the design staff to have looked at this occurrance and put in a computer programme to either limit the pilots choices (thereby avoiding the situation developing) when selecting a near VRS situation or putting in warning bells to alert of the onset of VRS.

Like all new flying consepts there is a lot to learn and its is either resolved by special flying techniques or by engineering.

There must be handling characteristics inherent in the V-22 which havent yet showed themselves. Thus it will be a long tough learning curve over the next years.

Incidentally does the rotor system have flapping hinges of any sort?

Lu Zuckerman

10th Dec 2002, 20:14

To: Tail Bloater

Incidentally does the rotor system have flapping hinges of any sort?

The Prop Rotor has lead and lag capabilities as well as feathering and flapping. The entire Prop Rotor has this capability essentially because the hub is made of rubber much like the elastomeric feathering bearings on some helicopters. The hub acts as a constant velocity joint, which minimizes if not, eliminates lead and lag but still allows feathering and flapping. The hub, at least when I worked on the program, has flapping sensors which send a signal to the flight computer. The flight computer in turn signals the flight control servos to cancel out the flapping much like a pilot of a conventional helicopter would do when moving forward from a hover.

I personally believe the following. 1) The V-22 is in a hover condition for a low proportion of the flight envelope. 2) Most pilots fear the fly-by-wire system and instead of flying the helicopter forward they will tilt the pods forward several degrees. 3) The overall life cycle of the hydraulic system including the servos is predicated by the low use of the servos while in the helicopter mode. When in the airplane mode the servos are in a fixed position dictated by the pilot (Prop pitch) and are assumed to remain stationary in the selected position. 4) When the aircraft maneuvers the Prop Rotor will respond like a gyroscope rotor and precess. The flap sensors will sense this and will be in almost constant motion trying to correct this condition. 5) If the flap sensors do not respond quickly enough the rotors will precess and the thrust line will go off axis causing control problems.

Even if the control problem is not manifested the hydraulics will be working overtime reducing system reliability from what was guaranteed by the contractor.

IMHO

:D

Skaz

30th Jan 2003, 22:15

I found this thread in the archives .... does anybody know what the present situation is re the training and delivery dates of first a/c ?

GLSNightPilot

31st Jan 2003, 03:18

The present situation is that everything is on hold. Bell has said the 609 program will be held up pending the outcome of the V22 program. Until the V22 is bought & delivered, don't expect any further development on the 609. It's years away from certification in the best case, completely dead in the worst.

Chuck K

25th Feb 2003, 09:43

http://www.rotorhub.com/images/heli/v22.jpg

U.S. Naval Air Systems Command (NAVAIR) officials confirmed that a test V-22 Osprey flew an unapproved route around Washington DC, but said the pilots have not been grounded. The aircraft - Osprey #21 - apparently strayed from its flight test route December 17. ‘The pilots made the diversion during a programmed test sortie from Pax River,’ says Ward Carroll, the test center’s spokesman.
Carroll says the pilots were cautioned ‘for extremely poor headwork’ by officials after the flight, but the flight itself was within NAVAIR guidelines. He said possible complications caused by the Osprey flying into Washington’s temporary flight restriction (TFR) area - imposed as the result of 9/11- had not been an issue. ‘The FAA has not been involved at all.’

But he could not explain how the aircraft was able to divert from an IFR flight plan to make a circular tour of the Pentagon. Such maneuvers are strictly banned under the terms of the TFR Carroll said no such flight route would be used again by an Osprey test crew.
The flight caused raised eyebrows. NAVAIR is currently processing a ‘Congressional inquiry’ from one Congressman who observed the aircraft. The Osprey is a ‘hot button’ issue in Washington DC following its recent record of accidents. It is currently under intense scrutiny- politically and operationally - during testing of alleged performance flaws.

---------------------------------------------------

[b]In a separate incident over Washington >>>>>>

Two F-15s were dispatched to investigate a television station's helicopter as it flew into controlled airspace, the apparent result of a communications failure between the pilot and the federal agencies that patrol the skies.
The WRC-TV (Channel 4) helicopter departed an airfield near Baltimore at about 10:15 a.m. The helicopter, which the station has dubbed Chopper 4 was sent up with a photographer to shoot live video of a traffic backup on Interstate 270.
"The F-15s were sent up to eyeball it. They determined it represented no threat," said Army Maj. Barry Venable, spokesman for the North American Aerospace Defense Command, a joint United States-Canadian military agency that patrols the skies around Washington.
The WRC crew was able to continue its work, station spokeswoman Angela Owens said.

The Federal Aviation Administration will investigate the incident, spokesman Greg Martin said.
Ms. Owens said there was a communications failure, but she did not know if it was human or mechanical.

News and traffic helicopters have been restricted from flying within a 15-mile radius of the Washington Monument since the September 11 terrorist attacks. This month, the FAA extended the area an additional 30 miles when federal authorities issued a Code Orange terrorism alert.

The Sultan

21st Mar 2003, 02:00

To all V-22 haters, "Iraqi Freedom" has proved you correct. The CH-53 continues its excellent record (Cambodia, Desert One, Afghanistan), the CH-46 is great and does not need replacing, and it is OK to let our troops be required to camp out within 10 miles of the enemy (thats to you LU).

Well Done!

The Sultan

:(

Ascend Charlie

21st Mar 2003, 04:50

You may have posted this one a bit soon - a CH-46 went down with the unfortunate loss of 16 lives.

if it had been a V-22, that would be the end of its chances. Being an old steam-driven 46, though, it might just be an "acceptable" loss. Sad how people think.

46Driver

21st Mar 2003, 06:13

The Pentagon is bringing out all its new toys for this war, but no Osprey - that's all you need to know about the MV-22......

Hilico

21st Mar 2003, 07:21

And if this had been fifty years ago, you would have been pointing out how the experiments in Korea with the new-fangled Bell 47s were doomed to fail as well?

Come to think of it, what DID happen to the helicopter after that? Anyone care to remind me?

Lu Zuckerman

21st Mar 2003, 14:59

To: The Sultan (Read official spokesperson for Bell helicopter)

By camping out 10 miles from the enemy are you alluding to my comment about the LHA positioning offshore? The positioning of the LHA was a part of the battle scenario and it would operate even closer depending on the enemies’ defensive capability.

I don't know if this plan has been modified to "camping out" over the horizon just because they were going to use the V-22. But even so with the higher speed of the V-22 it is still very vulnerable to enemy fire while in the helicopter mode.

I have worked for most of the major airframe manufacturers and two missile/spacecraft companies and I came to realize that none of the products I worked on were perfect. I would strongly suggest that you loosen up and stop being so defensive about Bell products. Oh yes I also worked for Bell Helicopter and I soon came to realize that none of their products were perfect.

It is my personal opinion that the last good helicopter to come off the Bell production line was the J-2 Ranger.

:rolleyes:

Tiercel

24th Mar 2003, 01:16

Well said Hilico.

Sultan - from what I have seen of this forum in the past couple of years, if it isn't Sikorsky, or if Nick didn't sez it, it ain't worth diddly.:rolleyes:

PPRUNE FAN#1

24th Mar 2003, 03:05

Hilico sez:
And if this had been fifty years ago, you would have been pointing out how the experiments in Korea with the new-fangled Bell 47s were doomed to fail as well?

Come to think of it, what DID happen to the helicopter after that? Anyone care to remind me?

Sure. Well, for one thing, we've learned a lot more about "settling with power." We call it "vortex ring state" now because we understand what the rotor is doing when the bottom falls out. We know how it happens, when it's likely to happen, and how to keep it from happening.

Yet it still happens. Crazy, that.

Also, we know more about formation flying, and how the rotor of one helicopter affects the rotor of another flying close by. And we've learned that it takes an enormous amount of computer power (maybe more than is currently available) to make two horizontal rotors fly in close formation especially when they are linked by a wing.

Yet despite this collective knowledge, some people continue their endeavor (futile struggle?) to make such a design work.

The V-22/609 does not introduce any "new" technology. It merely borrows a little from this and that to make a b*stard aircraft. The only envelope it pushes is that of helicopter performance (cruise speed), and it does that by making some very real sacrifices in others (safety being the most important, IMHO).

A helicopter that gets into fully-developed VRS low to the ground will surely crash. But it will probably crash in a level attitude. And that crash can be surviveable if the aircraft is designed well (UH-60 for instance) and the occupants are properly strapped-in.

A tilt rotor has a neat added feature: one proprotor can get into VRS while the other continues to fly. We call this mode "A-VRS" (asymmetrical vortex ring state). If the tilt rotor gets into A-VRS close to the ground it will roll over and hit that ground inverted or nearly so.

This has happened. Everybody onboard died. Everybody onboard the next one that gets into A-VRS will die too.

Tilt rotor fans minimize or trivialize this performance peculiarity as unimportant. "Oh, just teach the pilots how to avoid it," they cluck. I suppose they mean that we'll teach tilt rotor pilots to avoid A-VRS the way we've taught "regular" helicopter pilots to avoid plain-vanilla VRS over the years. Yeah, that ought to work- NOT!

But evidently the cruise performance gains with the tilt rotor are worth the increased risk (over a conventional helicopter) inherent in the design. Some will say that the ends justify the means.

I say: Have we learned nothing from fifty-plus years of helicopter development? Apparently not.

46Driver

24th Mar 2003, 03:33

How is the MV-22 going to handle MOUT (Military Operations in Urban Terrain) It does not have a gun for self defense - (and if it adds the chin turrent we keep hearing about, it just add more weight - the last thing the Osprey needs...), I doubt if it can fast rope, it is one big target while hovering, and how quickly can it get into a zone - remember, no big manuevers or we get vortex ring state. The price tag (last I heard was $79 million a copy) is JUST a tad expensive. Change the name from Osprey to Albatross....

The Sultan

28th Mar 2003, 11:30

Guy's

Here I am admitting everything you said is correct, and I get ridiculed. Whats up with that? Feeling defensive?

46Driver: I do not care to see what will happen if 46's lumber into urban combat.

Tiercel: Nick expertise shows on the 609 thread. You would think anyone with even minimal flight test knowledge could recognize the accomplishment of rock solid hovers and low speed maneuvers with a fly-by-wire control system all done on first flight of a revolutionary aircraft. But hey Nick sezs , range does not count, speed does not count. (As long as you have a bunch of tankers).

Lu: You are the highlight of my week. In the future the V-22 will be required so we can fly over or around all of our former friends.

The Sultan

46Driver

28th Mar 2003, 12:20

I don't think any helos (or tilt rotors) will do well in urban combat -and if I remember correctly, the V-22's are prohibited from landing in the desert on NVG's due to excessive rotor wash.

At least the 46 has 2 things: 1) machine guns for suppression and 2) it is affordable (the obvious replacement being a version of the H-60). The H-60 is much more versatile (DAP package, troop transport, etc..) so you can put a 4 to 6 helo package over on an LPD and do split-ARG operations 1500 miles away from the MEU (LHA / LHD based). The CH-53E is certainly more capable than the MV-22 (reference Rotor&Wing Jan 2002) - the only unique thing the V-22 can do is self deploy.

NASA made it to the moon with less time and less casualties than the Marine Corps in trying to get the Osprey operational. Face it: the Osprey is simply a jobs program to keep Bell Helicopter afloat.

Lu Zuckerman

28th Mar 2003, 21:49

To: The Sultan

When I worked on the V-22 program I had a conversation with several Boeing engineers. When we discussed autorotation they indicated that the ROD on the V-22 was 4-6000 FPM. It would seem to me that it would be very difficult to arrest that vertical descent.

I believe that the 609 was classified as a Powered Lift aircraft so that it would not be developed in accordance with AC: 29-2A which requires the demonstration of the ability to successfully autorotate.

:ok:

Nick Lappos

28th Mar 2003, 22:49

The Sultan has his turban wound too tight. Way too tight.

He misquotes me this way: "Nick expertise shows on the 609 thread. You would think anyone with even minimal flight test knowledge could recognize the accomplishment of rock solid hovers and low speed maneuvers with a fly-by-wire control system all done on first flight of a revolutionary aircraft. But hey Nick sezs , range does not count, speed does not count. (As long as you have a bunch of tankers"

Sultan, anytime you want to quote me, do so. Otherwise, try with all your might to stick to what I said. Simply put, tilt rotors do not have more range that helicopters. That is fact, and your wish that helicopters need "a bunch of tankers" to get tilt rotor range is just that, a wish.

Someday tilt rotors might become useful, but it will take a very long time for them to live up to the hype.

When you finish your career in Bell marketing, there is a job for you in Hollywood, I am sure. Bring your pprune posts along as job references.

PPRUNE FAN#1

29th Mar 2003, 05:22

Nick, Nick, Nick...

You've got to understand something about the tilt rotor true believers: There are those who have bought-into the idea of the tilt rotor so completely that they minimize or otherwise overlook *anything* that might be detrimental to the design. They believe, man. They believe. Don’t confuse them with facts.

I like how some of them call the tilt rotor "revolutionary." The tilt rotor is certainly *not* revolutionary. If anything, it is evolutionary. Okay, FBW is new to helicopters, but not to fixed-wing.

The V-22 has some very real performance/handling issues. The true believers have absolutely no doubt that these will be satisfactorily and quickly disposed of (this despite fifty years of experimentation by Bell). 5,000 psi hydraulic system? Hey, works fine in the F-16. Asymm-VRS? No problem! Unarmed and can’t defend itself? Aw Jeez, you want everything? (Interestingly, even during all of this down-time we still have had no word of a gun even being experimented with.)

The Marines and Bell are quick to put out any positive tilt rotor news that they possibly can. That is understandable. The future of the U.S. Marine Corps probably hinges on the success of the tilt rotor. We know that the future of Bell Helicopter does. My personal feeling is that any negative news is being discretely squelched or sat-on. For instance, if any of these new flight tests resulted in components having to be replaced, I imagine that news might not be immediately released.

The really strange thing is how the sanity, intelligence and patriotism of those who raise doubts about the viability of the tilt rotor is questioned. I guess I’m just not a true believer.

The Sultan

29th Mar 2003, 10:27

Nick,

Hollywood is your venue, not mine. Convincing people that the S-92 is new concept and that a $60M scout helicopter is viable does require the best PR writers Hollywood has.

By the way congrats on VFR certification on the S-92. Hope you can get IFR and Cat A cert sometime in the future.

The Sultan

Nick Lappos

29th Mar 2003, 23:19

The Sultan,

At least you didn't misrepresent my words!

The issue you Tilt Rotor fanatics face is to separate beliefs and wishes from facts. When the USMC general lamented that things would have been different in Afghanistan if only he had V-22's serves as an example. I guess nobody told him that the V-22 carries less and has shorter range than a Black Hawk when both are operated from 10,000 feet. It would be a similar sad story for Iraqi missions as well, where the 53's carry more than twice the payload, with more range, as well.

I do not dislike any new technology, in fact I am strongly supportive of change in all arenas, otherwise I'd have made a pretty lame chief R&D test pilot.

Your post started in the hole when you named it "V-22 Haters batting 1000" as if anyone who disagreed with you did so based on emotion ("haters") as opposed to facts. For the record, I do not "hate" any device, they are only machines, after all. The points I raised in the 609 thread that you misunderstood are statements of fact, but you believe them to be emotionally driven, because you are so driven.

If you woke up and smelled the coffee, you'd see that tilt rotors have certain advantages, are wonderful technology, and promise to help change things. But you'd also see that every day, helicopters take off with more range and more payload than the 609 or V-22, that helicopters don't need tankers to beat the TR's in range, that helicopters have better safety performance, better maintainability and cost less, too. Helicopters are slower, so the marketplace will decide if the extra speed is worth the other penalties.

It is a rough world out there, and Tilt Rotors have certainly earned no special treatment, even with "rock solid hovers". (If it had not been a "rock solid hover" would you have blamed it on pilot error, like the many V-22 accidents?) Expect a critical public, with sharp pencils, to ask you real questions, and compare those answers to real helicopters. If you respond with your invictive, you will only help make the hole you stand in that much deeper.

Lu Zuckerman

30th Mar 2003, 07:35

To: The Sultan

How about this? If the V-22 incurs minor structural damage of the aft fuselage that does not effect the structural integrity the Navy specified the method of repair that includes the usage of specified materials. The integrity of the repair is to be verified by X-ray examination. Boeing performed experiments using the specified materials and found them to be opaque to X-ray examination, which made it impossible to verify the integrity of the repair.

If the aft fuselage suffers major structural damage that restricts the V-22 from flying the aft fuselage must be removed and returned to the manufacturing facility for repair and curing in an autoclave using production tooling. This has a major effect on the availability of the V-22 at the squadron level. The V-22 may fly faster than a helicopter but it takes a year and a day to repair it and return it to operational status.

Since Bell and Boeing don’t talk to each other it would appear that you may have been unaware of this problem.

:ok:

The Sultan

31st Mar 2003, 04:08

Nick you said:

"When the USMC general lamented that things would have been different in Afghanistan if only he had V-22's serves as an example. I guess nobody told him that the V-22 carries less and has shorter range than a Black Hawk when both are operated from 10,000 feet. It would be a similar sad story for Iraqi missions as well, where the 53's carry more than twice the payload, with more range, as well."

So I guess now I am in no danger of ridicule for "misquoting" you.

Now. Lets project that a V-22 can not hover above 10K, I have not seen any UH-60's operating at 10000ft or above in Afganistan with any meaningful load or doing meaningful work. The tail rotor deficiences of the UH-60 apparently kept it out of the game and the Army had to mostly use CH-47's. You like to say V-22 supporters claim pilot error for crashes (which I never have, except maybe for the guy that went the wrong way on the blottle, Grady ?), but the UH-60 lobby sure went out of their way to blame the pilot of the Mount Rainer (?) crash which was filmed from above by a Bell 407. I thought that film clearly showed why 60's are limited in high altitude operations.

As to the USMC general, I am sure he speaks from what he knows, and not as a marketeer. Think like a user, with the V-22 : fewer or no tankers, a significantly greater area of operation on a tank of gas, and I want to get a package at a specific location and the 53's and 60's can not do it without unreasonable support.

If the UH-60 is the end-all why are you trying to sell the USMC the S-92? Why did the FAA have to make a special rule to allow "contingency" engine power for routine commercial operations for an aircraft with no military systems? I bet the S-92 with the same mission equipment as the V-22 (radar, warning systems, flares/chaff, armor, defensive weapons) will really be a great performer. I sure it can beat the V-22 in every category. Well Done!

The Sultan

Nick Lappos

31st Mar 2003, 06:23

Sultan, I hope you're not a flight test engineer for Bell! Wherever you got your degree from, write them and get a refund.

You can't even read, can you? What I said was "the V-22 carries less and has shorter range than a Black Hawk when both are operated from 10,000 feet". Nothing more and nothing less. You inferred the rest. The Marine Corps can find the right aircraft for the job, so stop proposing helicopter alternatives, OK?

In fact, the V-22 carries less than a Black Hawk at 10,000 feet, period. V-22 also cannot fly at 10,001 feet because that's its altitude limit. It has no yaw authority up there, none, that's why it is limited. Even if it could operate there, the payload of a V-22 is severely limited up there. According to its flight manual, at 10,000 feet, the V-22 hovers at 38,300 pounds gross weight, using 10 minute Interim Power, which leaves only 5,100 pounds for crew, fuel and troops and wishful thinking. The plain vanilla Black Hawk carries 5,500 pounds payload under the same conditions. Since the V-22 needs 11 pounds of gas to go a mile, and the Black hawk needs 8, the payload-range of a V-22 at 10,000 feet is worse than a Black hawk.

You prattle on about rumors of anti-torque limits, but you don't know what you are talking about, do you? At 10,000 feet, the H-60 has 35 knots sideward flight speed. Its in the flight manual.

I think flight manual data beats marketing hype every time. the same way a helicopter out lifts a tilt rotor, and goes farther every time.

Regarding "contingency" power, I guess you should get double your schooling money back. Contingency's what they call the single engine power these days, since about 30 years ago. Same "contingency" power the Bell 609 uses!

The Sultan

1st Apr 2003, 02:33

Nick Sez: "Sultan, I hope you're not a flight test engineer for Bell! Wherever you got your degree from, write them and get a refund."

Nick, You do not have to get hysterical here.

Roy thinks I do a great job and some Sikorsky guys think I am pretty good at what I do. I never commented on what I think of your piloting abilities,., so why get personal? I mean any guy that said the Comanche was ready for production after first flight ten years ago (?) can not be wrong.

Relative to your comments:

Why are UH-60's not being used in Afganistan for routine 10K+ operations? It was a briefing at AMCOM that talked about tail rotor issues on the UH-60 at altitude, is this true?. Relative to the Mt. Rainer crash, what was the cause? It must be published by now.

Relative to the use of contingency power on the S-92. I interpreted the FAA bulletin to mean it was for routine twin engine hover operations which is a new definition for contingency. (Note: I remember they said contingency, but they may have said it another way, anyway it required a new categoy of engine power not in the FAR's). The bottom line is the FAA indicates the S-92 routinely requires above spec engine power. As to the 609 engine power requirements you do not have a clue what we are doing so you should not comment on this. The FAA is the one that issued the "special" requirements on the S-92 not me. I did not see a word about the 609 in this document.

Tell Tommy, Steve and Jeff high.

The Sultan

Nick Lappos

1st Apr 2003, 03:41

Sultan,

When you make as many mistakes in your posts as you do, expect to be criticized.

Your assumptions about Black Hawk uses above 10,000 feet are wrong. Black Hawks continue to be used there routinely. The issues uncovered showed pilots needing to understand how to read the flight manual charts, in environments where the Army had not operated. The Black Hawk does very well up there, and carries more load than a V-22 could.

The Mt. Ranier crash seems to be a weight/power management issue, but it is still under investigation. The fact that you discuss a 407 flying at slow cruise above the crash site as some kind of proof of its better fitness is an example of the loose-cannon aerodynamics you seem to espouse. A Black Hawk can hover OGE with a loaded 407 on its cargo hook at higher altitude than a 407 can hover by itself.

You are also wrong about your home-grown definition of contingency power, and of the S-92's ratings. It shows a basic lack of understanding of thess issues.

rjsquirrel

29th Apr 2003, 01:54

Two recent press reports on the V-22's woes:

http://newsobserver.com/osprey/story/2492933p-2316427c.html

http://www.newsobserver.com/osprey/story/2492933p-2320669c.html

PPRUNE FAN#1

29th Apr 2003, 06:14

Hoo-man! This would all be funny if not for the billions of U.S. taxpayer dollars wasted on this turkey of an aircraft so far.

I loved the bit about the Air Force commissioning a study of the V-22 by a guy they knew and respected for a long, long time: Everest Riccioni. Then, when they didn't like the results of his study, they simply ended his contract and fired him. Priceless! Don't tell the U.S. Air Force anything it doesn't want to hear, you might get fired! I'm sure the USAF will insist now that it wasn't really a "study." Nah. Just a...oh...interoffice memo. Nothing important. "We just, you know, asked Riccioni to email us his thoughts."

Sure.

Then I had to laugh at the reliability studies. The one article stated:
Any advantage the Osprey gains in speed is canceled by the aircraft's poor reliability. It requires more maintenance and is less available for missions than the aging helicopters it will replace, according to reports from the Pentagon's director of operational test and evaluation.

The Marines point out that 19 studies have shown the Osprey to be more effective than helicopters. But the last of these reports was completed in 1994, and all were based on the assumption that the Osprey would work as promised.

Col. Dan Schultz, the Osprey program manager, said his engineers project that the Osprey will meet its reliability rates within the next two years. That's precious.

So the Osprey isn't even any more reliable than the 40-year old Sea Knights it's supposed to replace? Why am I not surprised. But you've got to love the chutzpah of the U.S. Air Force. "We're not going to tell you what the reliability rates are NOW, but believe us when we tell you that the aircraft will meet them if you just give us two more years."

Yes, and in that two years, the Osprey will surely get heavier and more expensive. The first article linked in RJ Squirrel's post makes it clear that the Osprey is falling miserably short of its Great Expectations. But none of that matters to those who are sold on the V-22. Heck, it could have the lifting capability and range and speed of a Bell 47 and they'd still think it was essential to the modern battlefield or some such nonsense.

Let's let Bill Lawrence, a pilot and former V-22 test program manager have the last word, because he puts it as succinctly as anyone: "If we don't get a machine to do the key performance parameters, then it won't do the missions we need it to do," Lawrence said. "That raises the question: Why are we buying this aircraft?"

The Sultan

24th May 2003, 11:19

Well the results are in. As one of his final acts Pete Aldridge has given two thumbs up to the program. Flight tests have, once again, proven the concept and all milestones have been met.

The Sultan:ok:

rjsquirrel

24th May 2003, 11:32

I guess we read two different versions, Sultan.
I heard that they approved another few aircraft, and permitted more testing. They decided not to cancel, yet, as I heard it. No?

SASless

24th May 2003, 20:39

Wonder if some of our technical experts....Shawn Coyle and that erstwhile Tee-Totaller Nick Lappos could provide a summary of the problems being encountered by the V-22 program....and describe the changes/modifications being made to the machine and flight techniques to counter the problems.

I realize Nick might be in a sensitive position here and not want to make any posts that are critical of the competition.....professional courtesy and all that being considered....but would be interesting to hear a "critical" analysis of the problems from a few who are involved in such issues on a daily basis.

Smoketoomuch

24th May 2003, 21:03

NL has commented on the V22 here before iirc. Perhaps a search will reveal? From memory the phrase 'damning with faint praise' was my impression of what he wrote.
Apologies to NL in advance if I misinterpreted his remarks.

MPT

3rd Sep 2003, 19:16

G'day All,

Came across this article on the Osprey HERE (http://www.g2mil.com/V-22struggles.htm) and thought some of you may be interested. It's all negative unfortunately, which may suggest that the author has his own axe to grind. The tilt rotor concept has always excited me, so hopefully the BA609 can survive even if the military version looks doomed currently.

Cheers,

MPT

The Sultan

3rd Sep 2003, 20:29

This is the same old s*** from the same old bunch of hysterical anti-V22 fanatics. They have continuously been proven wrong in the past and this feces laden article is just a continuation of their bias.

Now they criticize the V-22 team for catching and correcting vendor quality issues before any problems are encountered on an aircraft. Also any hydraulic leak becomes a "major crisis" to these morons. Lets ground any model of aircraft that has had a hydraulic leak in the last 12 months. OPPS, nothing will ever fly again.

The Sultan

Vfrpilotpb

3rd Sep 2003, 20:58

With the seal/rotor technology we have now I don't see why the concept of the "Fairey Rotordyne"(spelling) couldn't be rehashed, after all, the prospect of turning the rotors/engine packs of the V22 at the exact same deg/sec would seem to be always suspect and if happened would create a very large heap of Aloominum scrap! tinted with red:ouch:

RDRickster

3rd Sep 2003, 21:54

I was fortunate enough to talk with a V-22 test pilot when visiting a flight school a while back. (His friend was the Chief Instructor Pilot there). Anyway, he said there are too many political struggles for the program to survive - mostly because of the engineering problems.

He gave me an example of when a V-22 crashed because the control systems were accidently put in backwards! As far as a civilian model, I can't see how it would be cost effective.

Lu Zuckerman

4th Sep 2003, 03:31

To: The Sultan

This is the same old s*** from the same old bunch of hysterical anti-V22 fanatics. They have continuously been proven wrong in the past and this feces laden article is just a continuation of their bias.

It is difficult for a loyal employee to recognize and / or accept that there are problems relating to a program in which the employee is or might be involved in.

Some of the problems with the hydraulic system other than abrading of lines or possible deficiencies in tube wall thickness may be due to high cycle rates from the servo system.
When I worked at Boeing on the V-22 I consistently brought this subject up at each weekly design meeting. I mentioned repeatedly that one of the problems with high cycle rates had to do with the Proprotor©. Boeing management stated that it was a Bell problem. However Boeing designed the entire hydraulic system. Boeing never conveyed my complaints to Bell and even if they did, Bell could not make any changes. I left the program and nobody championed the solution to the problem.

:hmm:

PPRUNE FAN#1

4th Sep 2003, 10:26

Tiltrotor proponents laud the speed/range of the V-22 and its ability to "self-deploy" anywhere in the world. They might grudgingly admit that it is indeed not as big inside as the CH-46. But they carefully sidestep the importance and/or mere feasability of adding a gun, not to mention where to put such gun. And they downplay virtually every other demonstrated weakness of the design, either confidently claiming that the particular problems will definitely be solved, or dismissing them as simply not an issue given the incredibly compelling need for the "new" aircraft. Too, they do not brook any criticism of the aircraft at all (it is far too important to be criticized).

Very well.

I am not a fan of the V-22. I do not believe that it is "revolutionary" in any way. It might have been back when it was first being developed in the 1950's, but it is not now. I think the basic design is poor.

Mind you, I had to laugh at myself for not asking the most basic pilot-type questions about the V-22's purported performance: "At what altitude were the numbers derived?" It turns out that those very impressive figures were acheived at the unrealistically high altitude of 18,000'? In reality, the V-22 will live below 10,000 feet. Which makes all of its performance claims suspect. The ramifications of this are interesting. At least interesting insofar as how the V-22 proponents will rationalize them.

Speaking of laughing, the number of Marine officers who were key V-22 players until their retirement and who then ended up in high positions with V-22 contractor companies is more than humourous, it's astounding. If there was any objective good-will to be granted to the V-22, it is lost now. The fact that the project lives at all is a testimony to political pull than anything else. (Where did Freddy McCorkle end up again?)

My predictions:
1. The V-22 will not have a gun of any kind, nor a hoist, ever;
2. The V-22 will not even come close to meeting its design goals or objectives in terms of speed, distance or load-carrying capability;
3. Each individual V-22 will cost U.S. taxpayers about a kajillion dollars;
4. More V-22's will crash, killing all on board. Its fatal-accident rate will be shocking;
5. Items #1 through #4 will not matter one whit.
6. The V-22 program will continue, full speed ahead.

Lefthanded_Rock_Thrower

29th Nov 2003, 15:12

looking for performance details for the bell 609, HOGE charts, Norm and Emerg checklists. have contacted bell web page, no joy.

Do they cut the mustard ???.

Autorotate

29th Nov 2003, 15:26

Left Handed Rock Thrower

Drop me an email and will connect you with their test pilots. They should be able to help you.

Autorotate.

PPRUNE FAN#1

30th Nov 2003, 04:27

Say LeftHanded_Rock_Thrower, you might do well to conjure up some HOGE charts of your own. As little as Bell knows about the real, demonstrated performance of the 609, theirs would be as theoretical as yours.

As for the checklists, I doubt they're completely written yet. Last I heard, the lawyers, engineers, test pilots and salesmen were still wrangling over the exact wording of this part:

Asymmetrical Vortex-Ring State (A-VRS):
A. 2,500 FEET AGL AND ABOVE, AIRSPEED <60 KNOTS

1. At any time a lateral control input results in an increase of roll rate in the opposite direction, immediately perform:
a) Move stick in direction of roll;
b) Reduce power;
c) Beep nacelles forward;
d) Sign of the cross.

B. Successful recovery from fully-developed A-VRS at altitudes lower than (*unknown value*) feet has not been demonstrated.

The lawyers want it to read "2,500" and the engineers obviously want something lower. The test pilots are kind of quiet, shuffling their feet over in a corner.

The salesmen assure everyone that as long as there is a sufficient little warning in the AFM, pilots won't ever experience A-VRS at low altitudes, because as they put it, "...Pilots don't EVER make mistakes, and if they do make that mistake and kill the CEO of a Fortune 100 company - hey, it'll be their fault for violating the AFM in the first place! So there. Our conscience is clear. It's like regular helicopters! You don't hear about S-76's and Pumas ever crashing from pilot-error, do ya?"

Bell management is reported to have contemplated mass suicide over this "feature" of their new aircraft.

Lefthanded_Rock_Thrower

3rd Dec 2003, 15:52

does anyone know where i can obtain a copy of the Osprey POH, performance charts and system description ?. Thanks in advance.

BlenderPilot

22nd May 2004, 20:09

I really want to know how many V-22's have been built, I saw aircraft # 50 in Texas in Jan, does that mean there are more than that?

Gregg

24th May 2004, 13:12

A few more than 50 have been built. Aircraft #53 flew its first flight last week. There are several more getting close to first flight and several more on the assembly line.

Tony Chambers

4th Jul 2004, 23:29

does anyone have any information about chartering a boeing 609 tilt rotor in the uk.

Ian Corrigible

5th Jul 2004, 00:57

Not until 2007 at the earliest...

I/C

Banjo

5th Jul 2004, 20:19

out of interest does anyone know how the CAA will class the tilt rotors? fixed or rotary licence or yet another new one altogether with many many silly rules to aquire one.

belly tank

5th Jul 2004, 22:39

Banjo

I think you may find pilots will have to be dual rated, hold both commercial licences, IFR,ATPL ETC. dont quote me on this i just heard it somewhere about 12 months ago.

cheers BT

Tony Chambers

5th Jul 2004, 22:40

thats a good question and im sure someone will have the answer. i know that the us military on the v22 osprey have to do both lots of training. and its not quite vtol either.

NickLappos

6th Jul 2004, 04:50

In the US, the certification of tilt rotors has been careully planned, and a new FAR Part for tilt rotors has been drafted, bearing similarities to the airplane and helicopter sections of FAR where needed.

Pilots will have to be certified in the tilt rotor with a "powered lift" certificate, with emphasis on the limits and transitions, and use of simulators to a great extent. Here is a page that describes the training needed:

http://www.bellagusta.com/html/FAQs/BA609faqs.html#15special

Note - That page has one obvious error on it, where it says:
"What are the range comparisons between tiltrotor and helicopters? A tiltrotor will have somewhere between two and three times the range of almost any helicopter made." In point of fact, a tilt rotor has no great range advantage over a helicopter of the same empty weight and power. A modern helicopter always has a payload and range advantage over a similar tilt rotor, due to the much poorer payload capability of the tilt rotor.

The Boeing civil tilt rotor does not yet exist, and they have backed away from the Agusta-Bell 609, which is undergoing flight test (progress check, anyone?) The Bell web site is years out of date, it doesn't even mention the successful first flight of the 609 months ago.

Ian Corrigible

6th Jul 2004, 05:31

The first BA609 prototype logged 14 flight hours (all in helicopter mode) in 9 flights between March and May last year, after which it was subjected to a comprehensive teardown inspection. The aircraft is scheduled to resume flight testing in Q4, with the first of three Italian-based prototypes flying in Q1 2005. BAAC expects the BA609 certification program (being conducted under FAR Part Special Condition (21.17(b))) to take 3,000 flight hours, and is targeting joint FAA/JAA cert in 2007. BAAC claims 65 orders from 43 customers in 18 countries.

Nice ship, with clear benefits to those who can afford it, but I’m still surprised that 30% of those orders come from offshore operators, given the potential on-rig downdraft issue.

I/C

Tony Chambers

6th Jul 2004, 12:10

thanx for the feedback this project is definately 1 to watch. i am interested in the fact that the offshore market as taken on this machine. it will be interesting to see how it operates in extreme weather.

Robbo Jock

27th Aug 2004, 11:58

What's happening in the Tilt Rotor world ? As I understand it, the MV-22 is moving on, but what about the BA-609 ?

The Bell site's latest Program Update includes:

When functional system tests and ground runs are completed, the aircraft will be ready for first flight, anticipated for the second quarter of 2002 .

So not exactly up-to-date. Any more recent info ?

Gregg

27th Aug 2004, 12:35

BA 609 flew its first flight on 7 Mar 2003 and completed a 14 hour flight test program in helicopter mode.
It is scheduled to begin ground run testing for conversion mode later this fall and begin the full flight test program at the end of this year or early next year.

Here is a link to the last news release on the BHTI web site.

http://www.bellhelicopter.textron.com/en/companyInfo/pressReleases/pr_farnb2004_bellagusta.cfm

Robbo Jock

27th Aug 2004, 12:56

Thank you. They foxed me by having a different web-site. Here's me, fool that I am, expecting BA609 programme updates to be on the programme update page of the BA609 site !

gadgetguru

27th Aug 2004, 22:51

Was wondering about the tilt-rotors the other day, what is the story with an endorsement in those (tilt) types

would a pilot have to be both rotary & fixed wing or does this fall into a 3rd 'fuzzy' category?

just curious

JimL

28th Aug 2004, 17:29

Still in the melting pot; one expressed preference is that a pilot should be entitled to an endorsement from any licence providing the theory and competencies have been demonstrated on the conversion.

In plain terms that could be: a helicopter pilot has to demonstrate the fixed wing capabilities and problems of high(er) speed flight, stall and pressurisation; a fixed wing pilot the low speed helicopter manoeuvres; and both, the special elements of the Tiltrotor transitions (controlling the nacelles).

More difficult would be the ab initio training - but hey, who could afford that.

XEMS

28th Aug 2004, 19:21

United States has it all figured out. This is for the Private Pilot Powered-lift category. Of course this doesn't address how one goes about getting the training.

FAR 61.109e

(e) For a powered-lift rating. Except as provided in paragraph (i) of this section, a person who applies for a private pilot certificate with a powered-lift category rating must log at least 40 hours of flight time that includes at least 20 hours of flight training from an authorized instructor and 10 hours of solo flight training in the areas of operation listed in §61.107(b)(5) of this part, and the training must include at least—

(1) 3 hours of cross-country flight training in a powered-lift;

(2) Except as provided in §61.110 of this part, 3 hours of night flight training in a powered-lift that includes—

(i) One cross-country flight of over 100 nautical miles total distance; and

(ii) 10 takeoffs and 10 landings to a full stop (with each landing involving a flight in the traffic pattern) at an airport.

(3) 3 hours of flight training in a powered-lift on the control and maneuvering of a powered-lift solely by reference to instruments, including straight and level flight, constant airspeed climbs and descents, turns to a heading, recovery from unusual flight attitudes, radio communications, and the use of navigation systems/facilities and radar services appropriate to instrument flight;

(4) 3 hours of flight training in preparation for the practical test in a powered-lift, which must have been performed within the 60-day period preceding the date of the test; and

(5) 10 hours of solo flight time in an airplane or powered-lift consisting of at least—

(i) 5 hours cross-country time;

(ii) One cross-country flight of at least 150 nautical miles total distance, with landings at a minimum of three points, and one segment of the flight being a straight-line distance of at least 50 nautical miles between the takeoff and landing locations; and

(iii) Three takeoffs and three landings to a full stop (with each landing involving a flight in the traffic pattern) at an airport with an operating control tower.

helterskelter

30th Aug 2004, 05:56

Does anybody have any information about the ICAO Tilt Rotor Working Group that was supposed to be convened in order to produce relevant info for Annex 6?

JimL

30th Aug 2004, 06:20

They are at present working on all the subjects given to them. Next meeting will probably be in November.

visibility3miles

31st Aug 2004, 00:15

(I hope I'm not repeating a previous post.)

http://pubs.acs.org/cen/coverstory/8235/8235composites.html

August 30, _2004
Volume 82, Number 35
pp. 34-39
Chemical & Engineering News

COMPOSITE MATERIALS
Custom blending of materials with distinct characteristics leads to advanced composites with tailor-made properties

MITCH JACOBY, C&EN CHICAGO

Want to know the secret of Batman's success as a crime fighter? It's Robin. The fictional Caped Crusader didn't fight the dregs of Gotham City single-handedly--at least not in the TV series--because he could do his job more effectively with the Boy Wonder at his side. The Dynamic Duo, just as the name implies, worked as a team--each part complementing the other.

The idea that the whole can be greater than the sum of the parts isn't limited to superhero teams. It applies just as well to some real-world materials. By blending distinct components into composites, scientists and engineers make advanced materials with improved properties that outperform the constituents of the composites.

Plastics impregnated with glass or carbon fibers, for example, can be made tougher, stronger, and stiffer than the pristine plastic and fiber from which the composite is made. And by tailoring the composition and processing conditions, researchers can prepare custom materials endowed with combinations of properties that aren't found in other materials. The unique blend of properties has led manufacturers to replace steel and other conventional materials with advanced composites in many industries including aerospace, automobile, defense, and sports and leisure.

Blending two or more components to form composite materials isn't a new concept. Nature has been doing it for millennia. Bone, for example, a tough and rugged material, is a combination of brittle calcium phosphate and jellylike collagen. Other natural composites include shell, dentin, and tendon.

Synthetic composites have also been around for ages. But unlike natural composites, some of the oldest common synthetic examples, such as the interlocked wood and clay material used to build ancient dwellings, are based on mixing at a very coarse scale.

Finer composites--and the advanced properties they provide--were developed primarily after World War II in response to the aerospace industry's search for lightweight yet stiff replacements for common metals. Ultimately, the demand led to a large number of polymer-based materials, so-called metal-matrix composites, and other types of composites.

Although such materials have been used in commercial applications for decades, researchers continue to look for ways to improve materials' properties and performance and reduce costs. Some of the strategies include using new or modified components and developing new manufacturing processes. One approach that has drawn a lot of attention in recent years is incorporating nanometer-sized additives or nanoscale structure to make new types of engineering materials.

"ADVANCED COMPOSITES" typically refers to materials in which a polymeric resin (often called a matrix) serves as a kind of glue that holds a reinforcement material in place. Common matrix materials include epoxy, bismaleimide, polyimide, and phenolic (phenol-formaldehyde) resins. Reinforcements made from glass, carbon, boron, and other fibers impart stiffness and strength to the polymers, yet enable the products to remain lightweight.

Some 50 years ago, aircraft designers began taking advantage of the high strength-to-weight ratio associated with composites by replacing aluminum parts with others made from the newer materials. The design change helped reduce aircraft weight--thereby increasing fuel efficiency. In addition to lower weight, composites were also attractive to engineers because their resistance to corrosion and fatigue compares with metals.

The type of composite and extent to which the materials have been used in aircraft have changed over the years. For example, a few percent of fiberglass, which is a resin containing filaments made by drawing molten glass, was used in the 1950s in Boeing 707 passenger jets. By the 1960s, high-stiffness boron and graphite fibers embedded in epoxy resins became available, and the U.S. military focused on using these materials in rudders, ailerons, and other movable parts that control the motion of aircraft. Not long thereafter, boron fibers became widely used in the horizontal stabilizers of F-14 Tomcat fighter jets. And in today's F-22 fighters, carbon fiber composites and related materials compose nearly one-third of the jet's structure. Even greater reliance on composite materials is predicted for future military aircraft.

"We're moving from a force made up primarily of metal aircraft with riveted structures toward one that's making greater use of advanced compo sites," said Roland Cochran, polymers and composites branch head at the Naval Air Systems Command, Patuxent River, Md. Cochran's remarks were delivered last month in Washington, D.C., at the "Lightweight Materials for Defense" conference organized by the Institute for Defense & Government Advancement.

Cochran noted that some of the sophisticated capabilities of modern military aircraft wouldn't be possible without today's advanced composites. The V-22 (Osprey) tilt-rotor craft, for example, is able to take off, land, and hover like a helicopter, as well as reorient its rotors in midair and fly like a turboprop airplane. That kind of aeronautical split personality is due in part to the graphite-fiberglass rotors and other lightweight composite-based structures in the rotor system that are strong enough to tolerate high centrifugal forces yet remain slightly flexible.

Similarly, the extreme aerial maneuverability of F-18 fighter jets is partly due to composites used in the aircraft's wings, flaps, vertical and horizontal stabilizers, and other crucial parts.

Flying higher than military jets, satellites also benefit from composite materials. Cyanate-based resins are used by some designers, in preference to epoxies, because of the materials' inherent toughness, resistance to forming microcracks, and ability to withstand radiation damage.

[This is only part of the article. See link for the rest & the illustrations.]

Heliport

26th Sep 2004, 21:55

Star-Telegram feature V-22 Osprey faces new test
Test pilots have flown more than 2,000 accident-free hours since the hybrid aircraft, which was grounded for 18 months, returned to the air in 2002. Program officials say the V-22's capabilities are unmatched by conventional helicopters. But, as a new round of testing is scheduled to begin, questions remain about its cost, reliability and suitability for combat.
The dual-engine V-22 cruises like an airplane and takes off and lands like a helicopter. The propellers are forward as the aircraft cruises. To prepare for landing, the pilot tilts the propellers upward. In full helicopter mode, the propellers function as rotors, allowing vertical landings. The V-22 lands like a helicopter on the deck of a Marine amphibious assault ship. Its wings are rotated and the propellers folded for storage.

Is it reliable?
• Issue: Maintaining a technically complex aircraft.
Critics say
The V-22 is harder and more expensive to maintain than existing helicopters. Low maintenance costs are a military requirement.
Supporters say
Performance is improving as refinements are made.

Is it safe?
• Issue: Aerodynamics upon landing. A phenomenon known as vortex ring state, in which a rotorcraft loses lift after encountering its own downwash while descending at high speed, can cause the V-22 to roll.
Critics say
The V-22 is more susceptible to the problem than conventional helicopters, and flight rules calling for slower descents are unrealistic in combat.
Supporters say
Flight tests have shown that the V-22 can descend safely and that it is less likely to encounter the problem than conventional helicopters.

• Issue: Emergency landings
Critics say
Unlike a helicopter, the V-22 cannot perform a controlled vertical landing should it lose both engines to enemy fire or malfunction.
Supporters say
Losing both engines to a malfunction is extremely unlikely. If it does occur, the pilot can switch to airplane mode and glide to a landing.

Can it perform the mission?
• Issue: Brownouts. The V-22 generates a strong downwash on landing that can kick up dust and debris, obscuring the pilot's view.
Critics say
The V-22 is more susceptible to brownouts than conventional helicopters, rendering it ill-suited for desert environments such as Afghanistan or Iraq.
Supporters say
Downwash is an issue for all rotorcraft. The V-22 pilot can angle his thrust and rely on advanced instrument displays to overcome the problem.

• Issue: Small cargo space.
Critics say
Space is a significant problem. Military vehicles such as the Humvee do not fit into the cargo compartment, and it will be costly to buy smaller vehicles.
Supporters say
The smaller space is necessary to allow the V-22 to be used on ships. New vehicles are being developed to fit.

• Issue: High-altitude performance.
Critics say
It has not been proved that the V-22, with its smaller rotors, can make vertical landings in the mountains while carrying troops or cargo.
Supporters say
Future tests will show that the V-22 can land safely in the mountains.

Can costs be cut?
• Issue: The aircraft currently costs about $74 million.
Critics say
The cost, which has climbed over the years, outweighs the benefits.
Supporters say
They hope to trim the cost to $58 million apiece by 2010.

Estimated production cost per aircraft
In millions
1986 $24
1989 $35
2004 $74
Any thoughts on this analysis?

Robbo Jock

26th Sep 2004, 22:18

I must say I like the:

Future tests will show that the V-22 can land safely in the mountains

A little like the sign in pubs: "Free beer tomorrow"

The Rotordog

26th Sep 2004, 23:08

That particular newspaper, the Ft. Worth, Texas, Star-Telegram has been extremely critical of the V-22 so far. So that article was surprisingly "fair and balanced" (as one of our faux news cable t.v. channels bills itself). But I wonder if there was not just a hint of tongue-in-cheekiness to it?

With regard to maintenance, the V-22 will never be "easy" or "inexpensive." It is a hideously complicated piece of machinery which will certainly give technicians nightmares for generations to come. I predict that the military will downplay, minimize, falsify, fudge or directly try to decieve the American public as to the true mission availability of the aircraft. They have done it before, they will do it again.

With regard to VRS, it's all been hashed out before too.Supporters say
Flight tests have shown that the V-22 can descend safely and that it is less likely to encounter the problem than conventional helicopters.Yes, well.... "Less likely." That's putting the best "spin" on the subject, I suppose. The problem is, if a helicopter gets into full-blown VRS at a low altitude (where it will happen), the resulting crash is not necessarily fatal. In the V-22, if one proprotor goes into VRS close to the ground, the aircraft rolls inverted and hits the ground that way. Worth it anyway? Supporters say yes.

Issue: Emergency Landings.Supporters say
Losing both engines to a malfunction is extremely unlikely. If it does occur, the pilot can switch to airplane mode and glide to a landing.Yes, well... What makes the V-22 particularly vulnerable are those two engines/proprotors spaced so widely apart. If one were to take a missile hit which severs the driveshaft linkage to the other side, the aircraft will roll over and crash inverted. Worth it anyway? Supporters say yes. (This is not to say that helicopters are not vulnerable in their own ways.)

Issue: Cargo Space:Supporters say
The smaller space is necessary to allow the V-22 to be used on ships. New vehicles are being developed to fit.They've already got a vehicle that will fit inside. It's called a Jeep. I wonder how much money they're going to spend re-inventing it?

Issue: High altitude performance.Supporters say
Future tests will show that the V-22 can land safely in the mountains.Robbo Jock already dealt this one and nothing more need be said. But I'll say it anyway. You would think that since the V-22 first began flying, it's high-altitude performance would be quantified by now. Why the delay? Waiting for more powerful engines before publishing the "official" numbers? But yes, we will keep coming back for the free beer tomorrow.

Costs?Critics say
The cost, which has climbed over the years, outweighs the benefits.And here the Supporters take the completely opposite view: No matter what faults or weaknesses the V-22 has, no matter how expensive it gets, the benefits far outweigh them. Look, if Dick Cheney could not cancel the thing, nobody can. The V-22 will be fielded. You can be sure that the military will be working overtime to find an application- any application at all- for it so they can proudly point their fingers and say, "See? We told you it was worth it!"

Hey, have they put a gun on that thing yet? Or do they still intend for it to go into the field without any ability to defend itself?

rjsquirrel

26th Sep 2004, 23:35

• Issue: High-altitude performance.
Critics say
It has not been proved that the V-22, with its smaller rotors, can make vertical landings in the mountains while carrying troops or cargo.
Supporters say
Future tests will show that the V-22 can land safely in the mountains

This is surely a joke! According to its flight manual, the V-22 can carry less payload than a Black Hawk to 10,000 feet on a standard day. That means a 50,000 pound monster Tilt Rotor with 13,000 horsepower cannot carry what a 20,000 pound helicopter with 3500 horsepower can carry.

The joke continues.

RDRickster

26th Sep 2004, 23:47

Costs, maintenance, and size issues are very important. However, the key issue is combat effectiveness and how they relate to those issues. Let's assume requirements for major conflicts where armies are at war with each other (we won't go into other operational requirements, like urban or gorilla warfare, yet).

To win a battle and the war, you must take your enemies ability to wage combat against you FROM that enemy. Sometimes, it CAN be boiled down to economics (albeit rather simplistic). Example...

Previous version of the shoulder fired Dragon missle could penetrate almost any armor the previous Soviet block had. Soviets spent millions of rubels to develop and implement reactive-armor (small explosive charges mounted to the skin of their tanks that explode outward, preventing the incoming missile's shape charge from penetrating their armor). The U.S. solution was to spend about $36 dollars to put an 18" probe on the end of the missle... probe explodes reactive armor, clears the way, and the main missle body does it's job. (By the way, the current version of the Dragon missile has independant tracking abilities and will actually attack the target from the top... weakest point on tank is usually the top of the turret).

Can't we meet current operational requirements with less money and have more beef? I'd rather have a CH-53 with 1/2 of the troop capacity but have 7.62 mm mini-guns mounted on the side and the ability to carry a HMMMV (army jeep). Also, there are more options for true VTOL aircraft than the V-22.

Besides, if you REALLY need a light forced-entry capability, you can send the Rangers, the 82nd ABN, or Forest Recon. I'm not even counting small unit insertions like Special Forces or Navy Seals or SAS. I've been out of the game for a long time, but I don't see an operational requirement that the V-22 can fill in a hot zone. If a Slick or Blackhawk takes a few holes, it's back in the theatre of operations in a short-period of time... can't see that with the Osprey.